I want to get healthy.

I really do. I pretty much eat junk now with an occasional fruit. I don't excersize much except for walking. I have a newborn and I can't go to the gym or buy excersize equipment, I do have an elliptical machine though. Please help me out. I don't even know how to begin eating healthy, what do I make ? What do I buy? My SO won't want to eat healthy and I'm scared he can't afford buying me healthy food and him not. What can I do at home excersize wise to see improvement? I can always go for walks and stuff too. I'm 5'3 and 148 lbs. I'd love to lose 15-20 lbs. I just had a baby like I said, I love my pregnancy body. First time in my life I ever loved my body. Now I'm back to hating it with a vengeance!! I suck so bad at trying to get healthy, only way I've ever lost weight is from anxiety and no appetite. What's a mom to do? Can anyone give me recipes or meal ideas as well as work outs? Like I said cost effective, idk if this is even possible but it's worth a try.